Hello @ELJXMCEU1,
Let me walk you through the steps on how to customize your email messages to show the transaction numbers when sending invoice to your customers.
- Go to the Gear icon.
- Under YOUR COMPANY, select Accounts and Settings.
- Select Sales.
- On the Messages section, select the Pencil icon.
- Below the Sales form menu, select Invoice.
- Enter the following text as your email subject line: Invoice [Invoice No.] and/or your company name.
- Select Save.
- Click Done.
In the same manner, I've also included this reference for a compilation of articles you can use while working with us: Sales and Customers for QuickBooks Online.
If there's anything else that I can help you with, please let me know in the comments below. I'll be here to lend a hand.
